def write_file(file_name, content):
    """
    将指定内容写入指定文件
    :param file_name: 文件名
    :param content: 文件内容
    """
    with open(file_name, "w") as f:
        f.write(content)


def read_file(file_name):
    """
    读取指定文件内容
    :param file_name: 文件名
    :return: 文件内容
    """
    with open(file_name, "r") as f:
        return f.read()


def get_file_extension(file_name):
    parts = file_name.split(".")
    if len(parts) > 1:
        return parts[-1]
    return ""
